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Biomedical subjects

M A Woods

Publications and source records attributed to M A Woods.

12 recordsLinked to original sources
PubMed1998

Estimated skin exposure as an indicator for comparing radiovisiography (RVG) versus conventional Ektaspeed Plus dental radiography.

An Everest 3000 Radiovisiography (RVG) Video system (Trophy USA Inc., Fredericksburg, VA 22402) was compared with conventional radiography using Ektaspeed Plus film (Eastman Kodak Co., Rochester, NY 14650). Previous studies of the RVG system with a special computer controlled x-ray timer (Trophy USA, Inc.) claimed a significant reduction in radiation. Trophy has also claimed that the RVG system can provide diagnostic quality images utilizing existing conventional x-ray generators. This study used a conventional timer and generator. Since it would be logical to assume that many practitioners would use the equipment "in place" rather than invest in new, unfamiliar equipment. Estimated Skin Exposure (air) was used as the primary criteria for comparative purposes. Exposure has been defined as "a measure of radiation quantity, the capacity of ionize air. The roentgen (R), is the traditional unit of radiation exposure measured in air"; The results indicate that the RVG system when combined with a standard conventional timer actually generated greater radiation exposure than does standard, routine radiography.

Evaluation Studies as Topic↗
PubMed1996

A survey of the presence of a new infectious bronchitis virus designated 4/91 (793B).

On the basis of virus isolation and the demonstration of specific neutralising antibody in sera, infectious bronchitis virus (IBV) 4/91 (commonly called 793B) has been shown to be present in broiler, breeder and layer flocks of chickens in many parts of western Europe and also in Thailand and Mexico. These flocks had all been vaccinated against infectious bronchitis and the need for improved methods to control this new virus, still prevalent at least four years after it was first isolated, is discussed.

Animals↗
PubMed1993

An analysis of causes of apical root resorption in patients not treated orthodontically.

With few exceptions, most cases of external apical root resorption have no evident etiology, particularly when root blunting from orthodontic treatment has been ruled out. This study determined the frequency of apical root resorption in the permanent dentition of patients who had not been treated orthodontically. Associations between the occurrence of external apical root resorption and three measures of oral health--number of missing teeth, periodontal probing depths, and alveolar crestal bone heights--were also examined. Between 7% and 10% of the 306 patients exhibited obvious apical resorption. Strong statistical associations were found between the occurrence of external apical root resorption and loss of teeth, increased periodontal probing depths, and reduced crestal bone heights; ie, root resorption was significantly more common in teeth with compromised support. Loss of stability from adjacent teeth, increased use of fewer remaining teeth, and loss of the root's anchorage in the bone are significant predictors of external apical root resorption.

Adolescent↗
PubMed1993

Dental health patterns in an urban Midsouth population: race, sex and age changes.

Little is known about the oral health of American blacks. In particular, have they experienced the same reductions in dental caries and improvements in oral health as has the majority culture during the past several decades? A contemporary series of patient records (n = 300) was examined to test for age, sex, and race (American black and white) differences in an urban Midsouth population. Tooth loss was strongly age progressive in blacks and whites, but the rate was much greater in blacks. Periodontal probing depths also tended to be greater in blacks, particularly for the maxillary anterior teeth. The pattern of tooth loss with age in blacks is similar to rates recorded for the whole United States in the early 1960s. Subsequently, whites have tended to experience substantial improvements in oral health (ie, fewer decayed, missing, and filled teeth and less tooth loss); blacks in this sample have not exhibited this improvement.

Adolescent↗
PubMed1990

Age-progressive changes in pulp widths and root lengths during adulthood: a study of American blacks and whites.

The intertwined effects of normal aging processes and time-progressive diseases produce systematic changes in many oral and dental tissues. This cross-sectional study of pulp dimensions and root lengths in sound teeth tested for changes with age in adulthood while controlling for differences in gender and race (black, white). Age was the paramount determinant of pulp size which decreases via the accumulation of secondary dentin. In some instances the rate of change increases in older adults with an inflection point at 35-40 years of age. In contrast, root lengths are statistically independent of age once gender (male greater than female) and race (black greater than white) are controlled. Causes of the lack of association with age are discussed.

Adolescent↗
PubMed1990

Oral ulcerations.

Ulcerations are common occurrences in the mouth. Causes include physical trauma, radiation, chemical injury, and microbial infection (bacterial, viral, and fungal). Some ulcerations, such as recurrent aphthous stomatitis, Behçet's syndrome, and erythema multiforme, are of uncertain etiology, whereas others (eg, pemphigus, pemphigoid) are apparently of immunologic origin. Malignant neoplasms also may present as ulcerations. Because the natural history and treatment varies with the diagnosis, the practitioner should become familiar with the clinical appearance of the various types of ulcerations so that appropriate treatment can be instituted.

Bacterial Infections↗